Battery case

Abstract

This provides a battery cooling structure that allows for more even cooling of the battery module. [Solution] A lower case 10 and an upper case 20 are provided, with the upper case 20 having an upward opening. The upper case 20 is provided with a first member 30 which constitutes the front part of the upper case 20 and is fixed to the lower case 10, and a second member 40 which constitutes the rear part of the upper case 20 and is fixed to the lower case 10 in a state not fastened with the first member 30. The second overlapping portion 43 which constitutes the front end of the second member 40 is superimposed on the first overlapping portion 33 which constitutes the rear end of the first member 30, so that the upper end position H40 of the second member 40 is lower than the upper end position H30 of the first overlapping portion 43.

Description

Technical Field

[0006] , ,

[0005] ,

[0001] The present invention relates to a battery case.

Background Art

[0002] As disclosed in Patent Document 1, in a vehicle equipped with various electrical devices, a battery unit including a battery and a battery case for housing the battery is mounted at the rear of the vehicle.

[0003] In a vehicle in which a battery unit is mounted at the rear of the vehicle, there is a risk that a collision load is applied to the battery case from the rear in the event of a rear-end collision of the vehicle. In Patent Document 1, in order to solve the problem that the battery case moves forward as the collision load is applied from the rear, the base plate constituting the lower part of the battery case is composed of two members arranged in the front and rear and these are connected by a cutting pin, and when the vehicle is rear-ended, the rear base plate moves forward to suppress the forward movement of the front base plate. A configuration is disclosed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As a possible problem that occurs when a collision load is applied to the battery unit from the rear, apart from the movement of the battery case described above, there is a risk that the battery case is damaged and the contents of the battery case are exposed to the outside. A state in which the contents of the battery case are largely exposed to the outside is not preferable because it increases the possibility that an operator or the like may come into contact with the inner parts of the battery case unexpectedly. The invention of Patent Document 1 does not sufficiently consider this point and there is room for improvement.

[0006] This invention has been made in view of the above circumstances, and aims to provide a battery case that can prevent the contents of the battery case from being exposed to the outside when a vehicle is rear-ended. [Means for solving the problem]

[0007] To solve the above problems, the present invention provides a battery case that is mounted on the rear of a vehicle and houses a battery body inside, comprising a lower case that opens upward and an upper case provided above the lower case and covering the opening of the lower case, wherein the upper case includes a first member that constitutes the front part of the upper case and is fixed to the lower case, and a second member that constitutes the rear part of the upper case and is fixed to the lower case in a state not fastened to the first member, wherein the second overlapping portion that constitutes the front end of the second member is located below the first overlapping portion that constitutes the rear end of the first member and is superimposed on the first overlapping portion, and the upper end position of the second member is lower than the upper end position of the first overlapping portion.

[0008] With this configuration, the second overlapping portion forming the front end of the second member and the first overlapping portion forming the rear end of the first member are stacked vertically, so that the upper case is composed of the first and second members arranged front to back, while preventing the contents of the battery case from being exposed to the outside through the gap between the first and second members. Furthermore, since the first and second members are not fastened to each other, in the event of a rear-end collision, the impact load applied to the upper case from the rear can be relieved by the forward displacement of the second member. Moreover, since the second overlapping portion is positioned below the first overlapping portion and is stacked on top of it, and the upper end position of the second overlapping portion is set lower than the upper end position of the first overlapping portion, the forward movement of the second member is not restricted by the first member. Therefore, the impact load can be reliably relieved by the displacement of the second member, preventing damage to the upper case, and preventing the contents of the battery case from being exposed to the outside as a result of the damage to the upper case.

[0009] In the above configuration, preferably, the leading edge of the second member is hemmed (Claim 2).

[0010] This configuration allows for increased rigidity of the second member through a simple process of hemming the leading edge of the second member. Consequently, damage to the second member itself during a rear-end collision can be prevented. Furthermore, the forward displacement of the second member when a collision load is applied to the battery case from the rear can be minimized, thereby more reliably suppressing the transmission of the collision load to the first member and, consequently, preventing damage to the first member.

[0011] In the above configuration, preferably, the second member has a main body portion that covers the opening of the lower case and a vertical wall portion that extends downward from the rear edge of the main body portion along the rear surface of the lower case (Claim 3).

[0012] With this configuration, when the second member is displaced forward, the vertical wall portion bends upward, allowing the gap between the main body of the second member and the lower case to be covered by the vertical wall portion, thereby preventing the inside of the battery case from being exposed through the gap.

[0013] In the above configuration, preferably, the second member has a bead portion that bulges upward and extends in the vehicle width direction (Claim 4).

[0014] This configuration increases the rigidity of the second member, preventing it from being damaged during a rear-end collision. Furthermore, the bead portion extends in the vehicle width direction, which suppresses deformation and forward displacement of the second member when a collision load is applied to the battery case from the rear over a wide area in the vehicle width direction.

[0015] In the above configuration, preferably, the bead portion is located behind the second overlapping portion, and the lower surface of the second overlapping portion and the upper surface of the first overlapping portion are planar (Claim 5).

[0016] According to this configuration, by providing a bead portion on the second member to increase its rigidity, it is possible to prevent a gap from occurring between the second overlapping portion and the first overlapping portion by bringing them into surface contact.

[0017] In the above configuration, preferably, the trailing edge of the first member is bent upward by hemming (Claim 6).

[0018] According to this configuration, the liquid flowing on the upper surface of the first member can be received at the trailing edge of the first member, preventing the liquid from entering the inside of the battery case through the gap between the first member and the second member.

[0019] In the above configuration, preferably, the first member has a bulging portion provided at a position spaced forward from the first overlapping portion and bulging upward, and the battery body is disposed below the bulging portion (Claim 7).

[0020] According to this configuration, it is possible to secure a housing space for the battery body and prevent the second member and the battery body from colliding when the second member is displaced forward.

Advantages of the Invention

[0021] As described above, according to the battery case of the present invention, it is possible to suppress the contents of the battery case from being exposed to the outside during a rear-end collision of the vehicle.

Brief Description of the Drawings

[0022] [Figure 1] It is a schematic plan view showing the structure of the rear part of a vehicle equipped with a battery case according to an embodiment of the present invention. [Figure 2] It is a schematic plan view showing the inside of the battery case. [Figure 3] It is a schematic perspective view of the battery case. [Figure 4] It is a schematic perspective view showing the battery case disassembled. [Figure 5] It is a schematic view of the battery case seen from the rear. [Figure 6] It is a sectional view taken along line VI-VI of FIG. 5. [Figure 7] It is a sectional view showing an enlarged part of FIG. 6. [Figure 8] It is a schematic plan view showing the state of the battery case at the time of rear-end collision of the vehicle. [Figure 9] It is a sectional view taken along line IX-IX of FIG. 8.

Embodiments for Carrying Out the Invention

[0023] FIG. 1 is a schematic view showing a vehicle equipped with a battery having a battery case according to an embodiment of the present invention. FIG. 1 shows a part of the rear portion of the vehicle 1. Hereinafter, the front-rear direction of the vehicle 1 will be simply referred to as the front-rear direction, the traveling direction when the vehicle 1 advances will be referred to as the front, and the opposite side will be referred to as the rear. Also, the direction orthogonal to the front-rear direction in a plan view will be referred to as the left-right direction, the right side when facing the front will be referred to as the right, and the opposite side will be referred to as the left. Further, the direction orthogonal to the front-rear direction and the left-right direction will be referred to as the up-down direction, the ground contact side of the vehicle 1 will be referred to as the bottom, and the opposite side will be referred to as the top.

[0024] A floor panel 2 constituting the lower surface of the vehicle body is provided at the rear portion of the vehicle 1. The vehicle 1 of the present embodiment is a vehicle in which a luggage room R2 is partitioned behind the passenger compartment R1, and the floor panel 2 constitutes the floor surfaces of the passenger compartment R1 and the luggage room R2. A cross member 3A extending left and right and bulging upward is provided between the portion of the floor panel 2 constituting the floor surface of the passenger compartment R1 and the portion of the floor panel 2 constituting the floor surface of the luggage room R2. Further, on both left and right side portions of the floor panel 2 constituting the floor surface of the luggage room R2, rear side members 3B, 3B extending front and rear and bulging upward are provided respectively.

[0025] A battery unit 5 is disposed in the luggage room R2. The battery unit 5 has a battery 51 (hereinafter referred to as the battery main body 51) and a battery case 6. The battery case 6 is a box-shaped member that partitions an accommodation space inside, and houses the battery main body 51 inside.

[0026] The battery unit 5 is mounted on the upper surface of the floor panel 2 in the luggage compartment R2. In this embodiment, the battery unit 5 is located in the center of the front of the luggage compartment R2 in the left-right direction. The battery unit 5 has a roughly rectangular parallelepiped shape and is mounted on the floor panel 2 in an orientation that extends in the left-right direction. The appearance of the battery unit 5 is formed by the battery case 6. That is, the battery case 6 has a roughly rectangular parallelepiped shape and is mounted on the floor panel 2 in an orientation that extends in the left-right direction. Although not shown in the figures, the area above the battery unit 5 is covered by an openable and closable plate-shaped trunk panel, which is a panel member on which occupants can place luggage, etc.

[0027] Figure 2 is a schematic plan view showing the inside of the battery case 6, and is a general plan view of the battery unit 5 with the upper case 20, which will be described later, removed. Inside the battery case 6, in addition to the battery body 51, a cooling duct 52 for cooling the battery body 51, a BCM (Battery Control Module) 53 for controlling the charging and discharging of the battery body 51, etc. are housed.

[0028] The battery body 51 is located at the front of the battery case 6. The battery body 51 consists of two battery modules 51A, 51A, each containing multiple battery cells. As shown in Figure 5, which will be described later, the two battery modules 51A are arranged side by side in the vertical direction. The two battery modules 51A, 51A have the same structure as each other. Each battery module 51A has a roughly rectangular parallelepiped shape extending in the left-right direction. In this embodiment, each battery module 51A contains multiple battery cells made of lithium-ion batteries.

[0029] The cooling duct 52 has a shape that extends horizontally along the battery body 51. The cooling duct 52 is located behind the battery body 51. A cooling pipe 54 extends from the cooling duct 52 to the outside of the battery case 6, and the cooling duct 52 supplies cooling air introduced from the outside of the battery case 6 to the battery body 51 through the cooling pipe 54. The BCM 53 has a roughly rectangular parallelepiped shape. The BCM 53 is located above the cooling duct 52. Although not shown in the illustration, various high-voltage components are located inside the battery case 6 in addition to those mentioned above.

[0030] Figure 3 is a schematic perspective view of the battery case 6. Figure 4 is a schematic perspective view of the battery case 6 in an exploded view. Figure 5 is a view of the battery case 6 from the rear. Figure 6 is a cross-sectional view taken along line VI-VI in Figure 5. Figure 7 is an enlarged view of a portion of Figure 6.

[0031] The battery case 6 includes a lower case 10 that opens upward and an upper case 20 that is provided above the lower case 10 and covers the opening of the lower case 10.

[0032] The lower case 10 includes a lower case body 11 that internally partitions the space for housing the battery body 51 and the like, and a pair of left and right mounting parts 12, 12. The lower case body 11 and the mounting parts 12, 12 are integrally formed with each other. For example, the lower case 10 is made of cast aluminum.

[0033] The lower case body 11 has a roughly rectangular box shape that extends to the left and right and opens upwards. A portion of the cooling pipe 54 is integrally formed with the lower case body 11 on the rear side wall. Although not shown in the illustration, the lower case body 11 also has multiple through holes through which various cables extending from the BCM 53 and the like are inserted.

[0034] The mounting sections 12, 12 extend outwards to the left and right from the rear ends of both the left and right ends of the lower case body 11. As shown in Figure 1, the mounting sections 12, 12 are connected to the rear side members 3B, 3B by bolts or the like. In addition, the front end of the lower case body 11 is provided with a mounting section (not shown) to which a bracket 90 is attached, and as shown in Figure 1, the lower case body 11 is connected to the cross member 3A via the bracket 90. Through these connections, the lower case 10, and by extension the battery case 6 and battery unit 5, are fixed onto the floor panel 2.

[0035] The upper case 20 is divided into two parts, front and rear, and includes a first member 30 that constitutes the front part of the upper case 20 and a second member 40 that constitutes the rear part. As shown in Figure 6, the rear end 33 of the first member 30 and the front end 43 of the second member 40 are superimposed in the vertical direction, and the opening of the lower case body 11 is entirely covered by these first member 30 and second member 40. In this embodiment, in the front-rear direction, the dimensions of the second member 40 are shorter than those of the first member 30, and the second member 40 covers the area of ​​the opening of the lower case body 11 from a position behind the center in the front-rear direction to the rear. The first member 30 and the second member 40 are made of plate-like members that are thinner than the lower case 10. In this embodiment, both the first member 30 and the second member 40 are made of steel plate. However, the first member 30 and the second member 40 are made of different materials, with the second member 40 having higher tensile strength than the first member 30, and thus the second member 40 is less prone to cracking than the first member 30.

[0036] The first member 30 has a substantially rectangular shape that extends in the left-right direction when viewed from above. The first member 30 includes a bulging portion 31 located at its front and bulging upward, and an extension portion 32 extending rearward from the rear edge of the bulging portion 31.

[0037] As shown in Figure 6, the bulge 31 includes a battery module housing 31A that constitutes the region from its front end to near the center of the bulge 31 in the vertical direction, and an inclined portion 31B that constitutes the region from the rear edge of the battery module housing 31A to the rear edge of the bulge 31. The battery module housing 31A constitutes the part of the first member 30 that has the largest vertical dimension. Specifically, the vertical dimension of the battery module housing 31A is generally constant in the front-rear direction. On the other hand, the vertical dimension of the inclined portion 31B decreases towards the rear, and in a side view, the inclined portion 31B is inclined diagonally downward and rearward from the rear edge of the battery module housing 31A.

[0038] The battery body 51 is located below the bulging portion 31. Specifically, the battery body 51 is located below the bulging portion 31 with a portion of the battery module 51A located above it housed inside the battery module housing portion 31A. In this embodiment, the vertical dimension of the battery body 51 is set to be slightly smaller than the dimension between the top surface of the battery module housing portion 31A and the bottom surface of the lower case body 11, and the battery body 51 occupies an area up to near the top surface of the battery module housing portion 31A.

[0039] The extension portion 32 extends substantially horizontally to the rear from the trailing edge of the inclined portion 31B. Specifically, a first bead portion 38 is formed on the upper surface of the first member 30, extending in the front-rear direction and bulging upward. In this embodiment, multiple first bead portions 38 are formed spaced apart from each other in the left-right direction. The first bead portions 38 extend from near the front end of the battery module housing portion 31A to near the center of the extension portion 32 in the front-rear direction. In the portion of the extension portion 32 where the first bead portions 38 are provided, a step is formed such that the rear side is positioned lower than the front side. On the other hand, as shown by the dashed line L32 in Figure 6, the other portion of the extension portion 32 extends substantially horizontally.

[0040] The rear end portion 33 of the first member 30, which is overlapped vertically with the front end portion 43 of the second member 40, is formed by the rear portion of the extension portion 32. Hereinafter, this rear portion of the extension portion 32, which is overlapped vertically with the front end portion 43 of the second member 40, will be referred to as the first overlapping portion 33. The first bead portion 38 stops near the front end of the first overlapping portion 33, and the first overlapping portion 33 is almost entirely flat.

[0041] The rear edge 33A of the first overlapping portion 33, that is, the rear edge 33A of the extension portion 32 and the first member 30, is bent upward by hemming. Specifically, the rear edge 33A of the first overlapping portion 33 is configured such that the plate-like members constituting it are folded upward by 180°, so that the two plate-like bodies overlap vertically and form a roughly U-shape that opens forward in a side view, and the lower plate-like body is configured to be continuous with the portion in front of the rear edge 33A of the first overlapping portion 33.

[0042] The first member 30 has a flange portion 34 that extends along the left and right edges and the front edge of the bulge portion 31 so as to surround the bulge portion 31. The flange portion 34 extends substantially horizontally. The outer peripheral edge 35 of the flange portion 34 is bent upward along almost its entire circumference. The lower surface of the flange portion 34 and the upper surface of the lower case body 11 are in surface contact. The first member 30 is fixed to the lower case body 11 by bolts 91 connecting the flange portion 34 to the lower case body 11.

[0043] The second member 40 has a substantially rectangular shape that extends in the left-right direction when viewed from above. The second member 40 has a second member body 41 that extends substantially horizontally and a vertical wall portion 44 that extends downward from the rear edge of the second member body 41. In this embodiment, both the left and right edges 45 of the second member body 41 are bent upward over almost their entire length. As shown in Figure 6, the second member body 41 extends along the upper surface of the lower case body 11 and covers the rear portion of the opening of the lower case body 11. The second member body 41 corresponds to the "main body portion" of the present invention.

[0044] As shown in Figure 6, the vertical wall portion 44 extends downward from the rear edge of the second member body 41 along the rear surface 11A of the lower case body 11 and the lower case 10. In this embodiment, the second member body 41 extends behind the rear end of the lower case body 11, and the vertical wall portion 44 extends vertically along the rear surface of the lower case body 11 at a position spaced rearward from the rear surface. The vertical dimension of the vertical wall portion 44 is set to be smaller than the vertical dimension of the lower case body 11. As shown in Figure 4, etc., the vertical wall portion 44 is provided along almost the entire rear edge of the second member body 41.

[0045] A second bead portion 48 is formed near the center of the second member body 41 in the front-to-back direction, extending in the left-to-right direction and bulging upward. The second bead portion 48 is formed over almost the entire length of the second member body 41 in the left-to-right direction. The second bead portion 48 corresponds to the "bead portion" of the present invention.

[0046] The front end portion 43 of the second member 40, which is superimposed vertically with the first overlapping portion 33, is composed of the portion of the second member body 41 that is in front of the second bead portion 48. In other words, the second bead portion 48 is formed behind the front end portion of the second member 40 that is superimposed vertically with the first overlapping portion 33. Hereinafter, this front end portion of the second member 40 that is superimposed vertically with the first overlapping portion 33 will be referred to as the second overlapping portion 43.

[0047] The front edge 43A of the second overlapping portion 43, that is, the front edges 43A of the second member body 41 and the second member 40, are bent downward by hemming. Specifically, the front edge 43A of the second overlapping portion 43 is folded downward by 180° so that the two plates overlap vertically and form a roughly U-shape that opens to the rear when viewed from the side, and the upper plate is configured to be continuous with the second member body 41 behind the front edge 43A.

[0048] As shown in Figure 6, the first overlapping portion 33 and the second overlapping portion 43 are superimposed such that the second overlapping portion 43 is below the first overlapping portion 33. Both the upper surface of the second overlapping portion 43 and the lower surface of the first overlapping portion 33 are planar. The upper surface of the second overlapping portion 43 extends along the lower surface of the first overlapping portion 33 and is in surface contact with that lower surface.

[0049] As shown in Figure 6, the second member 40 has a shape in which its upper end position H40 is lower than the upper end position H30 of the first overlapping portion 33. Specifically, the second member 40 is highest at the top P1 of the second bead portion 48, and the upper end position H40 of the second member 40 is at the position of the top P1 of the second bead portion 48. The first overlapping portion 33 is also highest at its rear edge 33A, and the upper end position H30 of the first overlapping portion 33 is at the upper end position of the rear edge 33A of the first overlapping portion 33. The second member 40 is formed such that the position H40 of the top P1 of the second bead portion 48 is lower than the upper end position H30 of the rear edge 33A of the first overlapping portion 33.

[0050] The lower surface of the second member body 41 and the upper surface of the lower case body 11 are in surface contact. The second member 40 is fixed to the lower case body 11 by bolts connecting both left and right ends and the rear end of the second member body 41 to the lower case body 11.

[0051] The first member 30 and the second member 40 are individually fixed to the lower case body 11 in an unfastened state, that is, not fastened to each other.

[0052] (effect, etc.) As described above, the battery unit 5 according to the above embodiment is located at the rear of the vehicle 1. Therefore, there is a risk that a collision load will be applied to the battery unit 5 from the rear during a rear-end collision. Figure 8 is a schematic plan view showing the state of the battery case 6 when a collision load F is applied to the battery unit 5 and battery case 6 from the rear due to a rear-end collision by the vehicle. Figure 9 is a diagram showing a part of the cross-section along line IX-IX in Figure 8.

[0053] As shown in Figure 8, the lower case 10 and upper case 20 deform in response to a rearward collision load F. In the example in Figure 8, the rear of the lower case 10 and upper case 20 deforms forward near the left and right center. If the upper case 20 is damaged as a result of this deformation and the contents of the battery case 6 are exposed to the outside, there is a risk that occupants or workers may come into unexpected contact with the battery body 51 or high-voltage components housed inside the battery case 6.

[0054] In contrast, according to the battery case 6 of the above embodiment, the collision load applied to the upper case 20 can be relieved by the displacement of the second member 40, thereby suppressing damage to the upper case 20. Therefore, exposure of the inside of the battery case 6 during a rear-end collision can be suppressed.

[0055] Specifically, in the above embodiment, the upper case 20 is divided into two parts: a first member 30 that constitutes its front part and a second member 40 that constitutes its rear part. The first member 30 and the second member 40 are not fastened to each other but are individually fixed to the lower case 10. Therefore, when a collision load F is applied to the upper case 20 from the rear, as shown in Figure 8, the second member 40 deforms, but deforms while being displaced forward, and the collision energy is consumed by the forward displacement. Therefore, according to the above embodiment, the amount of deformation of the second member 40 and the resulting strain in the second member 40 can be kept small, and damage to the second member 40 can be suppressed. Also, as shown in Figures 8 and 9, the second member 40 moves forward relative to the first member 30. Therefore, the transmission of the collision load F applied to the second member 40 to the first member 30 is suppressed. Consequently, damage to the first member 30 is also suppressed.

[0056] In particular, in the above embodiment, the second overlapping portion 43 of the second member 40 is positioned below the first overlapping portion 33 of the first member 30 when it is overlapped with the first overlapping portion 33, and the upper end position H40 of the second overlapping portion 43 is set lower than the upper end position H30 of the first overlapping portion 33. Therefore, interference between the second member 40 and the first member 30 is suppressed, and the second member 40 can be moved smoothly. Consequently, the second member 40 can be reliably displaced forward, and the transmission of the collision load F to the first member 30 can be reliably suppressed, thereby reliably suppressing damage to the first member 30 and the second member 40. In addition, because the first member 30 and the second member 40 are overlapped in the vertical direction, the upper case 20 is divided into two members, while preventing the inside of the battery case 6 from being exposed through the gap between the two members.

[0057] Furthermore, in the above embodiment, a bulging portion 31 is provided that bulges upward at a position spaced forward from the first overlapping portion 33 of the first member 30, and the battery body 51 is positioned below the bulging portion 31. As a result, the dimensions of the battery case 6 in the front-to-back direction can be kept small while securing space for housing the battery body 51, and the battery body 51 and the second overlapping portion 43 and thus the second member 40 can be spaced apart in the front-to-back direction to prevent interference between the battery body 51 and the second member 40 when the second member 40 is displaced forward.

[0058] Furthermore, in the above embodiment, the leading edge 43A of the second member 40 is hemmed. Therefore, with this simple configuration of hemming the leading edge 43A of the second member 40, the rigidity of the second member 40 can be increased, and deformation of the second member 40 when a collision load is applied to the second member 40 can be suppressed, thereby more reliably preventing damage to the second member 40 itself. In addition, the amount of displacement of the second member 40 toward the front, i.e., toward the first member 30 can be kept to a minimum, preventing the collision load from being transmitted to the first member 30 and thus suppressing damage to the first member 30 as well.

[0059] Furthermore, in the above embodiment, the second member 40 has a bead portion 48 that bulges upward and extends in the vehicle width direction. Therefore, the rigidity of the second member 40 can also be increased by the bead portion 48. In particular, because the bead portion 48 has a shape that extends in the vehicle width direction, deformation and forward displacement of the second member 40 can be suppressed over a wide area in the vehicle width direction. Consequently, when a collision load is applied to the battery case 6 from the rear, the amounts of the first member 30 and the second member 40 can be reduced, and damage to them can be suppressed more reliably.

[0060] In this case, if the bead portion 48 is provided on the second overlapping portion 43, there is a risk that a gap will occur in the vertical direction between the second overlapping portion 43 and the first overlapping portion 33. In contrast, in the above embodiment, the bead portion 48 is provided behind the second overlapping portion 43, and the lower surface of the second overlapping portion 43 and the upper surface of the first overlapping portion 33 are planar. Therefore, while providing the bead portion 48 on the second member 40, the lower surface of the second overlapping portion 43 and the upper surface of the first overlapping portion 33 can be brought into surface contact to prevent a gap from occurring between them.

[0061] Furthermore, in the above embodiment, the second member 40 is provided with a vertical wall portion 44 that extends downward from the rear edge of the second member body 41 along the rear surface 11A of the lower case body 11. In this structure, as shown in Figure 9, when the second member 40 is displaced forward by an impact load F, in particular when the second member 40 is displaced forward relative to the lower case 10, the vertical wall portion 44 is bent upward by contact with the upper end of the rear surface 11A of the lower case body 11. Therefore, as shown in Figure 9, even if the second member 40 is bent upward from the upper surface of the lower case body 11 by an impact load F, the gap between the second member 40 and the upper surface of the lower case body 11 can be covered by the vertical wall portion 44. Thus, it is possible to prevent the inside of the battery case 6 from being exposed through the gap. In addition, the rigidity of the second member 40 can be increased by the vertical wall portion 44, and the displacement and deformation of the second member 40 can be suppressed.

[0062] Furthermore, in the above embodiment, the rear edge 33A of the first member 30 is bent upward by hemming. Therefore, as shown by the arrow Y100 in Figure 7, when a liquid such as water travels along the upper surface of the first member 30 and reaches the rear edge 33A of the first member 30, the liquid can be received by the rear edge 33A of the first member 30. This prevents the liquid from reaching the boundary between the rear edge 33A of the first member 30 and the second member 40 and seeping into the inside of the battery case 6 through the gap between them.

[0063] (modified version) In the above embodiment, the case in which the battery unit 5 is mounted in the luggage compartment R2 of the vehicle 1 was described. However, the battery unit 5 only needs to be mounted in the rear part of the vehicle 1, that is, in the rear part when the vehicle 1 is divided into two equal parts in the front-to-rear direction, and its mounting location is not limited to the luggage compartment R2.

[0064] Furthermore, although the above embodiment described a case in which the battery body 51 is a battery containing battery cells made of lithium-ion batteries, the type of battery body 51 is not limited to this. Also, the material of the battery case 6 is not limited to the material of the above embodiment. [Explanation of Symbols]

[0065] 5 Battery Unit 6 Battery Cases 10 Lower Cases 20 Upper Case 30 First Member 31 Bulge 33 First overlapping section 33A Trailing edge of the first member 41. Second component body (main body part) 43 Second overlapping section 43A Front edge of the second member 44 Vertical wall section 51 Battery Unit (Battery)

Claims

1. A battery case mounted at the rear of a vehicle, which houses the battery unit inside, A lower case that opens upwards, The lower case is provided above the lower case and includes an upper case that covers the opening of the lower case. The upper case includes a first member that constitutes the front part of the upper case and is fixed to the lower case, and a second member that constitutes the rear part of the upper case and is fixed to the lower case in a state not fastened with the first member. The second overlapping portion, which constitutes the front end of the second member, is positioned below the first overlapping portion, which constitutes the rear end of the first member, and is superimposed on the first overlapping portion. A battery case characterized in that the upper end position of the second member is lower than the upper end position of the first overlapping portion.

2. In the battery case according to claim 1, A battery case characterized in that the leading edge of the second member is hemmed.

3. In the battery case according to claim 1, The battery case is characterized in that the second member has a main body portion that covers the opening of the lower case and a vertical wall portion that extends downward from the rear edge of the main body portion along the rear surface of the lower case.

4. In the battery case according to claim 1, The battery case is characterized in that the second member has a bead portion that bulges upward and extends in the vehicle width direction.

5. In the battery case according to claim 4, The bead portion is located behind the second overlapping portion, A battery case characterized in that the lower surface of the second overlapping portion and the upper surface of the first overlapping portion are planar.

6. In the battery case according to claim 1, A battery case characterized in that the trailing edge of the first member is bent upward by hemming.

7. In the battery case according to any one of claims 1 to 6, The first member has a bulging portion that is provided at a position spaced forward from the first overlapping portion and bulges upward, The battery case is characterized in that the battery body is located below the bulging portion.

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